Over the past fifty years there has been considerable research concerning the detrimental effects on children of living in a single-parent family structure. This literature reveals that children from one-parent families are at high risk for the development of emotional and psychological disturbance. However, there has been almost no concern with aspects of this non-traditional structure which may promote the healthy development of children. Given current projections that as many as half the children born in the 1970's will spend several of their formative years in a one-parent home, research focused on the potentially adaptive qualities of one-parent families is clearly needed. The present study addresses this issue and will attempt to define parental leadership behaviors associated with the absence of psychopathology in these children. Study methods involve direct observation of mother-child interactions in dysfunctional and adaptive one-parent systems. Based on a paradigm developed in a pilot study, mother and eldest-child dyads from a clinic-referred and a non-clinic sample will be observed interacting under two task conditions, an instrumental task and a social-emotional task. Each group will consist of 25 mother-daughter and 25 mother-son pairs, yielding a total sample of 100 dyads. Multivariate and univariate analyses of variance will be employed to test the hypothesis that adaptive interactions will be characterized by more frequent leadership behavior by the mother. Also, there should be less symmetry in adaptive parent-child dyads than in dysfunctional ones, as revealed by time-series analyses of interaction data. Results of the study will provide normative data necessary for theory and model-building efforts regarding adaptive childrearing practices in these families. These data will also be useful in the development of primary and secondary prevention models based on a matching-to-sample philosophy.